Method and apparatus for heating rolls



March 29 1927. I I 1,622,286

R. L. MOINTOSH ET AL METHOD AND APPARATUS FOR HEATING ROLLS Filed March 1924 2 Sheets-Sheet 1 alga rolled. -Expressed in other language, during the preliminary heating the heat is of low intensity whereby to permit the relatively uniform distribution thereof throughout the rolls to prevent damage due to strains produced by too rapid local expansion, After the preliminary heating a heat at a higher intensity is applied to bring the rolls to the propertemperature and to the proper conformation at the same time.

It is an obj ect of the present invention to provide a new and improved method and ap aratus for heating rolls.

t is a further object to provide apparatus of this character which is relatively light and which may be moved about and applied to the rolls without moving them from the roll stands.

- It is an additional object to provide a heater in which the degree of heat may be controlled and in which distribution of the heat to the various portions of the roll'may be roperly' taken care of.

I? is also an object of the present invention toprovide heating means in which the heat may be transmitted to the rolls by direct metallic contact.

Other and further objects of the invention will appear as the description proceeds.

Efiorts have heretofore been made to heat rolls by the application of steam jackets or by blowing heated air or gases upon the rolls. These methods do not allow for an adequate temperature range or" control of the temperature, or of application of differing amounts of heat to the various portions of the roll. Moreover, they do not allow.

for the application of heat by the most economical method of direct metallic contact. Since the rolls vary in diameter and contour due to variation in heat, it is essential that the heating means be flexible if it is ,to maintain contact with the rolls throughout the heating ope-ration.

We have illustrated inthe accompanying drawings, a preferred embodiment of our invention. It a In these drawin Figure 1 is an e evation with the heating means applied to the rolls in the stand, the rolls being shown in section;

Figure 2 1s a view on an enlarged scale.

of a portion of Figure 1, showing in detail the connection of the heating elements;

"Figure 3 is a fragmentary view showing the heater applied to the rolls as seen from the right of Figure 1;

Figure 4 is a detail view, partly broken away showing one of, the heating elements; F1 re 5 is a fragmentary view illustrating t e contact of the heating element with a the roll; amr Figures 6, 7 and 8 are somewhat diagrammatic v1ews illustrating circuits suitable for our heating means.

Referring particularly to Figure 1, the upper roll 11 and lower roll 12 are shown supported in ausual type of roll stand 13. This roll stand which is of usual construction, forms no part of-our present invention and will not be described in detail. The roll heater comprises two separate elements A and B, one of which is applied to each side of thepair of rolls. These elements are exactly similar and the description. of one ap lies to the other. The elements comprise a rame 14 of angle bars from which the handles 15 extend-at the upper end and the rollers 16 extend at the lower end. The two elements A and B are clamped together by means of the bolts 17 and 18 at their upper and lower ends. The flexible jacket members 19 are secured to the upper portion of the frame and the similar jacket members 20 are secured to the lower portion of the frame. It Will be noted that the jackets 19 and 20 are secured to the frames 'only through a small portion of their periphery, the remainder of which remains flexible and free to be drawn in contact with the rolls. The adjusting bolts 21 are threaded through ing the upturned edges 24.- and 25 of the jackets 19 and 20.

As shown indetail in Figure 2 the jacket 19,is provided with a lining 26 of asbestos or similar heat insulating material. plurality of heating elements 27 are secured upon the inner face of the insulating material and are provided with the connector lugs 28.- The several heating elements are connected in parallel by the connectors 29.

portions not in direct contact with heating elements. It is to be understood, however,

that although the greatest efliciency is.

accomplished maintaining the heating elements in contact with the roll, it is possible to heat the roll without direct nietallic contact. j .1 1 Referring now to Figure 5, the heat ele-.

ment 27 is shown in," full lines in its normal or cooled state. how the element will be bowed. outwardly when it expands upon being heated. This outward bowing of the element will force it into intimate contact with the roll 11.

One form of heating element is shown in The i In dotted lines is indicated the transverse frame members 22 and are provided with the enlarged ends 23 engag-l from such elements'to the rolls during an initial heating period at a relatively low rate, whereby the heat is distributed through the roll in a manner to minimize internal stresses, and subsequently connecting such heating sections in series parallel whereby the rate of heat supply is increased.

10. In combination, a roll, a pair of electrical heating elements extending longitumemes dinally of said roll, each of said heatingio elements comprising a resistor arranged to have a varying heating efl'ect longitudinally of the corresponding element.

Signed at Chicago, Illinois, this 26th day of Feb, 1924.

ROBERT L. MCINTOSH. GORDON FOX. 

